CLASSPATH: The Hadoop jars must be added prior to running your
TensorFlow program. The CLASSPATH set by
${HADOOP_HOME}/libexec/hadoop-config.sh is insufficient. Globs must be
expanded as described in the libhdfs documentation:

shell
CLASSPATH=$(${HADOOP_HDFS_HOME}/bin/hadoop classpath --glob) python your_script.py
For older version of Hadoop/libhdfs (older than 2.6.0), you have to expand the
classpath wildcard manually. For more details, see
HADOOP-10903.

If the Hadoop cluster is in secure mode, the following environment variable must
be set:

KRB5CCNAME: The path of Kerberos ticket cache file. For example:

shell
export KRB5CCNAME=/tmp/krb5cc_10002

If you are running Distributed TensorFlow, then all
workers must have the environment variables set and Hadoop installed.